The special feature of the upper mantle is the asthenosphere.It is located just below the lithosphere and is made up of rocks that is fluid and can move.The fluidity of these rocks powered the movement of the tectonic plates on the earths crust.Circular convection cycles in the hot,fluid upper mantle rock move the plates over the surface of the earth.
<span>Unsafe passes are passes with restricted line of sight, passes with cross traffic, narrow passes which are unsafe.
Several collision can result from making unsafe passes. Some of them are:
-getting run off the road
-getting sideswiped
-getting hit head-on</span>
<span>b. The coefficient of static friction for all contacting surfaces is μs=0.35. neglect friction at the rollers.
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